Phrase review should be first-class, not a side effect of word saving

Single words are useful, but German becomes natural through reusable sentence pieces. Right now phrase work exists, but it still feels secondary.

I want phrase items to be visible as their own study lane: phrase cards, phrase streaks, phrase filters, and phrase exports. The point is to help people remember what Germans actually say in context, not just what a dictionary entry means.

If Butterfluent leans harder into phrases, it becomes more differentiated from generic flashcard apps.